Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For heparin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to heparin, to beef, or to pork. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Heparin has not been shown to cause birth defects or bleeding problems in the baby. However, use during the last 3 months of pregnancy or during the month following the baby's delivery may cause bleeding problems in the mother.

Breast-feeding—Heparin does not pass into the breast milk. However, heparin can rarely cause bone problems in the nursing mother. This effect has been reported to occur when heparin is used for 2 weeks or more. Be sure to discuss this with your doctor.

Children—Heparin has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.

Older adults—Bleeding problems may be more likely to occur in elderly patients, especially women, who are usually more sensitive than younger adults to the effects of heparin.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking heparin, it is especially important that your health care professional know if you are taking any of the following:

• Aspirin or
• Carbenicillin by injection (e.g., Geopen) or
• Cefamandole (e.g., Mandol) or
• Cefoperazone (e.g., Cefobid) or
• Cefotetan (e.g., Cefotan) or
• Dipyridamole (e.g., Persantine) or
• Divalproex (e.g., Depakote) or
• Medicine for inflammation or pain, except narcotics, or
• Medicine for overactive thyroid or
• Pentoxifylline (e.g., Trental) or
• Plicamycin (e.g., Mithracin) or
• Probenecid (e.g., Benemid) or
• Sulfinpyrazone (e.g., Anturane) or
• Ticarcillin (e.g., Ticar) or
• Valproic acid (e.g., Depakene)—Using any of these medicines together with heparin may increase the risk of bleeding

• Also, tell your doctor if you are now receiving any kind of medicine by intramuscular (IM) injection.

Other medical problems—The presence of other medical problems may affect the use of heparin. Make sure you tell your doctor if you have any other medical problems, especially:

• Allergies or asthma (history of)—The risk of an allergic reaction to heparin may be increased

• Blood disease or bleeding problems or
• Colitis or stomach ulcer (or history of) or
• Diabetes mellitus (sugar diabetes) (severe) or
• High blood pressure (hypertension) or
• Kidney disease or
• Liver disease or
• Tuberculosis (active)—The risk of bleeding may be increased

Also, tell your doctor if you have received heparin before and had a reaction to it called thrombocytopenia, or if new blood clots formed while you were receiving the medicine.

In addition, it is important that you tell your doctor if you have recently had any of the following conditions or medical procedures:

• Childbirth or
• Falls or blows to the body or head or
• Heavy or unusual menstrual bleeding or
• Insertion of intrauterine device (IUD) or
• Medical or dental surgery or
• Spinal anesthesia or
• X-ray (radiation) treatment—The risk of serious bleeding may be increased